Median isn’t the average and Matt was computing the average household Amazon spend.

You're conflating two different things, but what you point out is still useful because it suggests that there are a few people on the higher end who make a LOT more and are dragging the mean up when compared to the median. The mean is probably not as indicative of the fortunes of most Americans as GP suggests. $3000 is a lot of money for most families, but there are a few for which it's increasingly not only inconsequential, but more like a rounding error.